Business Segments - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue from third parties									$ 1,121,551	$ 1,138,361	$ 1,094,402
Revenue from other segments									0	0	0
Total revenue	$ 294,195	$ 270,850	$ 281,967	$ 274,539	$ 305,367	$ 288,523	$ 280,066	$ 264,405	1,121,551	1,138,361	1,094,402
Adjusted EBITDA									27,900	57,883	58,612
Total assets	622,676				649,638				622,676	649,638
North America
Segment Reporting Information [Line Items]
Revenue from third parties									777,426	780,511	736,140
Revenue from other segments									3,200	5,469	6,029
Total revenue									780,626	785,980	742,169
Adjusted EBITDA									61,780	74,230	68,434
EMEA [Member]
Segment Reporting Information [Line Items]
Revenue from third parties									260,950	265,669	267,168
Revenue from other segments									9,500	13,444	13,070
Total revenue									270,450	279,113	280,238
Adjusted EBITDA									6,410	15,242	14,752
Total assets	160,322				171,086				160,322	171,086
LATAM SEF [Member]
Segment Reporting Information [Line Items]
Revenue from third parties									83,175	92,181	91,094
Revenue from other segments									217	1,693	4,456
Total revenue									83,392	93,874	95,550
Adjusted EBITDA									3,082	4,278	6,818
Total assets	$ 43,028				$ 57,235				43,028	57,235
Other (2)
Segment Reporting Information [Line Items]
Revenue from third parties									0	0	0
Revenue from other segments									(12,917)	(20,606)	(23,555)
Total revenue									(12,917)	(20,606)	(23,555)
Adjusted EBITDA									$ (43,372)	$ (35,867)	$ (31,392)